This invention relates to a small switch, a pilot lamp or the like, and specifically, to a mounting frame equipped with a decorative plate, suited for mounting a small switch, a pilot lamp or the like. More particularly, the present invention relates to a mounting frame equipped with a decorative plate, for mounting a switch, a pilot lamp or the like that has a construction in which, when a mounting frame formed by a synthetic resin material having resiliency is placed on the switch main body or on the pilot lamp, a sleeve step-wise formed on the switch main body or the pilot lamp first engages with a through-hole of the mounting frame, and protuberances or recesses defined on both side surfaces of the switch main body or the pilot lamp then engage with recesses or protuberances of the mounting frame, or with recesses (or two protuberances or through-holes) formed on a bridge interconnecting both legs of the mounting frame, in the concavo-convex relation, so that the mounting frame can be fitted to the switch main body or to the pilot lamp in one-touch operation and the resulting switch or pilot lamp-mounting frame assembly can be fitted to a panel hole of an instrument or equipment in one-touch operation.
Conventional mounting frames equipped with a decorative plate of this kind have the construction such as shown in FIGS. 1 and 2. The detail of the switch construction is disclosed in Japanese Utility Model Publication No. 48,284/1978 granted on the Applicant of the present invention, by way of example.
However, the switch mounting frame 1 formed integrally of a synthetic resin material such as shown in FIGS. 1 and 2 is fitted to a switch main body 5 as leg portions 2 on both sides are engaged with the corresponding side surfaces of the switch main body 5 and protuberances 6 of the switch main body 5 are fitted into corresponding through-holes 3 at the lower end portions of the legs 2, respectively. Accordingly, when the switch is inserted and fitted to a panel 8, resilient plates 4 on the right and left sides of the mounting frame 1 are inwardly pushed at the time of mounting so that a force acts upon the point 4a and consequently, the resilient plates 4 operate as if they were a seesaw. As a result, the lower portions of the resilient plates 4, that is, the lower portions of the legs 2, float up from the switch main body 5 and come off from the protuberances 6. Namely, the leg portions 2 are likely to come off from the switch main body 5 due to the force in the switch operation of a push button switch 7, for example.
If the mounting frame 1 is used for a toggle or lever switch instead of the push button switch shown in FIGS. 1 and 2, the thickness of the leg portions is small and a force is applied between the switch and the mounting frame in the direction of thickness of the legs 2 and the resilient plates, but not in the direction of their width, upon operation of an operating element. For these reasons, the abovementioned seesaw operation is further enhanced and the leg portions undergo strain and shaking so that the mounting frame floats up from the panel, thereby losing stability. Obviously, the drawback of the former is further amplified in the latter.
Furthermore, since the leg portions 2 and resilient plates 4 are disposed on both right and left side surfaces of the switch (on both side surfaces corresponding to the switch operating direction in the case of a toggle switch or the like), the transverse width B' of the panel hole must necessarily be greater than that A' of the switch and hence, panel cut of a greater size is necessary.
In addition, shaking or unstability is likely to occur between the switch main body and the mounting frame even under the state in which the latter is fixed to the former, because the mounting frame is fitted to the switch main body as the protuberances 6 on both sides of the switch main body 5 are fitted into the through-holes 3 of the legs 2 of the mounting frame 1 but no other fixing means exists. Since the lowermost portions of the mounting frame consists only of the leg portions that are thin and narrow, they are likely to undergo deformation and to cause shaking when applied with a force in the direction of their thickness.